Influenza virus infection and release of progeny viruses both occur specifically at the apical plasma membrane in polarized epithelial cells. It was shown that the Nucleoprotein (NP) transported to the apical plasma membrane independent of other viral proteins during viral assembly. We have shown that NP interacts with actin microfilaments, and it is speculated that this interaction allows it to be transported to the apical plasma membrane. It was further shown in vitro that amino acids 338-340, 342, and 405 of NP are responsible for this interaction. Therefore, we are exploring the role of these amino acids in virus life cycle. These critical amino acids of NP (WSN and PR8) were mutated to alanine (F338A, E339A/D340A, R342A, and Q405A) in Pol I-II plasmid by site-directed mutagenesis. WSN and PR8 NP Mutants F338A, R342A exhibited growth and plaque morphology similar to WT virus during viral rescue. This showed that the respective amino acids were not essential in virus life cycle. Viral rescue for WSN NP E339A/D340A and Q405A, and PR8 NP Q405A were unsuccessful. Transfection and immunoprecipitation of WSN E339A/D340A and Q405A mutant NP showed that the mutant nucleoproteins were made but, likely, they did not form the vRNP complex. Plasmid containing PR8 NPE339A/D340A is under construction. Cellular localization of all the mutant proteins will be examined by confocal Immunofluorescence. To examine the cellular localization of E339A/D340A and Q405A mutant NP proteins among other viral proteins (i.e. wt virus infected and mutant NP transfected cells), Flag-tag strategy will be used.

Mikael Guzman Karlsson recently graduated from UCLA in 2007 with a dual degree in Neuroscience and Physiological Science as well as a minor in Scandinavian Studies. As an undergraduate student, Mikael worked in Dr. Alcino Silva’s lab studying the consolidation of memories and more specifically the cortical brain regions involved in the storage and retrieval of spatial memories.

Memory consolidation is defined as the process by which perceptual, motor, and cognitive information is encoded from a primarily vulnerable memory trace into enduring long-term memory. The mechanisms required for initial memory processing in the hippocampus have been extensively studied, specifically emphasizing the role of the hippocampus as crucial to the formation and storage or recent memories. However, much less is known regarding the machinery underlining permanent memory storage in cortical areas. Recent studies have begun to uncover the secrets of remote memory organization as well as pinpoint the network of cortical regions that support remote memory and the molecular events crucial for their consolidation. Through the use of a variety of techniques such as behavioral studies, neuroanatomic lesions, pharmacological activations, and immunohistochemistry, Mikael has been attempting to determine whether or not the retrosplenial cortex possesses a memory-related function when it comes to the storage and retrieval of spatial memories.

Currently, Mikael is continuing his research in Dr. Silva’s lab by working full-time as a paid staff research assistant. Within the next year, Mikael plans to apply to MD-PhD programs where he hopes to fuse his desire for neuroscience and medicine. He would like to thank Dr. Silva and everyone in the Silva Lab as well as Dr. Tama Hasson and everyone at the URC/CARE office for all the economic and intellectual support that allowed him to perform the research that he so greatly enjoys.

For the past three years in laboratory of Professor Sarah H. Tolbert at the Department of Chemistry and Biochemistry, I have been working on encapsulating the semiconducting polymer (MPS-PPV) using Cowpea Chlorotic Mottle Virus (CCMV). The experiments I have conducted with my graduate mentor, Benny Ng, have confirmed that we can use the polymers and viral capsid proteins to form spherical or tubular structures by controlling the physical conformation of the polymers in buffer. We are currently investigating how its fluorescence properties are related to the physical conformation of MPS-PPV inside of the capsids. My latest research project is to measure friction coefficient of cubic mesoporous titania using atomic force microscope.

Working in the Tolbert's lab has widened my exposure of different research interests and enabled me to realize why I enjoy research. In the classroom, students are often taught specific techniques and equations to obtain a solution. However, in research I am free to use my own imagination to find a variety of paths to the solution. Research is also different from many careers which reuse established knowledge to perform the same task routinely. Researchers, however, use established knowledge to make new discoveries in science and technology. Personally, I would rather be the one solving the puzzle than the one repeating the solution.

Isabel Neacato is a first year UC LEADS student and is majoring in biochemistry. She began working for the laboratory of Dr. Manuel L. Penichet last year. She works under the direct supervision of a post-doctoral fellow, Dr. Tracy R. Daniels, who together with Dr. Penichet is mentoring her. The Penichet’s laboratory is focused on the development of novel immunotherapeutics for the treatment of cancer.

Previous research has shown that the human transferrin receptor (hTfR) is responsible for the delivery of iron into cells through its binding to transferrin. The high TfR expression on the surface of cancer cells, up to 100-fold higher than the average of normal cells, its extracellular accessibility, and its ability to get internalized, make this receptor a promising tool for targeted immunotherapy of cancer. Utilizing this information, the Penichet’s laboratory developed a mouse/human chimeric antibody fusion protein composed of avidin genetically fused to a human IgG3 that specifically targets the ectodomain of the hTfR. Their initial goal was to use this molecule (anti-TfR IgG3-Av) as a universal vector to deliver biotinylated agents into cancer cells. However, they discovered that anti-hTfR IgG3-Av alone possesses a strong intrinsic anti-proliferative/pro-apoptotic activity against hematopoietic malignant cell lines. Importantly, this activity can be potentially enhanced by its conjugation to biotinylated therapeutic agents such as the plant toxin, saporin. Isabels’ early work focused on determining the specificity of this protein by its delivery of biotinylated saporin and the apoptotic pathway induced by such treatment. Her current work focuses on testing anti-TfR IgG3-Av in combination with other potential drugs in multiple myeloma model cell systems (IM-9 and U266 cell lines) to determine whether the therapeutic effect of the fusion protein can be enhanced. The effective drug concentration is determined by a dose-response, afterwhich it is tested in combination with anti-TfR IgG3-Av in order to determine whether a more potent growth inhibition can be achieved.

Geraldina Rodriguez is a 3 rd year undergraduate student majoring in Psychobiology. She is currently investigating under the mentorship of Dr. Christopher S. Colwell, in the Department of Psychiatry and Biobehavioral Sciences. Dr. Colwell’s research has focused on understanding the mechanisms underlying circadian rhythms in mammals.

Geraldina was previously conducting research on circadian regulation of learning and memory under the guidance of post-doctoral student Louisa Wang but just started doing her independent research project in the summer of 2007. Under the tutelage of Dr. Elizabeth Hernandez and Dr. Colwell, Geraldina has been studying the circadian dysfunction of mouse models of Huntington’s disease (HD). HD is a late-onset neurodegenerative disease characterized by the loss of specific cell populations in the brain, and the deterioration of motor and cognitive skills, as well as disrupted sleep patterns. Geraldina first wants to see if mice that are given treatments of the mitchondrial toxin 3-Nitropropionic Acid (3-NP) to pharmacologically induce both behavioral and physiological characteristics of Huntington’s disease will exhibit disrupted day and night time activity. By analyzing and measuring their wheel running activity in both a regular light/dark cycle and in continual darkness, Geraldina hopes to see that the mice treated with 3-NP were not able to synchronize their circadian rhythm to their environment as most organisms do, and therefore exhibit unstable and fragmented wheel running activity. This study could lead to further investigation in understanding alternative treatment strategies to counteract circadian dysfunction in patients with HD

Lauren Sanchez is a senior Molecular, Cell, and Developmental Biology major under the guidance of Dr. Luisa Iruela-Arispe. Her primary research focus is on the relationship of the female hormone progesterone and vascular homeostasis. Progesterone is used by women of all ages in both contraceptives and hormone replacement therapy. Studies by the Women’s Health Initiative have demonstrated users of hormonal therapy are at a greater risk for developing heart disease. Preliminary studies have suggested a link between expression of the progesterone receptor (PR) and vascular permeability, which may contribute to the development of heart disease. The widespread usage of progesterone warrants further study on effects of progesterone on the mammalian vasculature. To contribute to this study, Lauren has generated a reporter mouse model, in which the reporter gene lacZ has been substituted for the PR gene. Using the PRlacZ mouse model, she will characterize wild-type patterns of PR expression in mice of varying developmental stages. The model will be compared against other PR mouse models in which the PR is misexpressed, including PR conditional excision models, in which PR is deleted in specific tissues by Cre-mediated recombination. Preliminary analysis of one particular model, the VENPR, in which PR is deleted from the vascular endothelium, suggests important role of progesterone in suppression of the inflammatory response, especially at sites of vascular injury. Lauren will continue this study by challenging knockout mice with bacterial lipopolysaccaride (LPS) and subsequent analysis by immunohistochemistry. Lauren hopes to continue her studies in an MD/PhD program this fall.